Hp Proliant ML370 booting problem

I have two operating system installed on my machine, after two day, i boot my machine it is not responsing even not recognizing the operating system and show messages like replace and strike any key when ready etc.
i want to reinstall both operating system ie window server 2003 and RHEL 5.
how i format the scsi drive and make logical drive on the system.
Note: fdisk is not working properly.
shoaib

Hi,
First of all, try to see what happened to your disk
boot system with "Live CD" and mount some partition
cat you mount ? any error ?
also you can put first CD of redhat and boot system in rescue mode"boot
rescue"
and follow instruction and at last
execute grub-install DRIVE_NAME